Field of the Invention
The present invention relates to a focus detection apparatus including a configuration for detecting a focusing state and a configuration for controlling an indication of a focusing state.
Description of the Related Art
With a high definition camcorder supporting full high definition or 4K video capture, it is not easy for a photographer to implement precise focus adjustment by performing a manual focus operation (hereinafter, called an MF operation) on a subject. Particularly when a focus adjustment is performed by checking focusing on a viewfinder or a panel, for example, defocusing may occur which cannot be found on the viewfinder or panel, for example.
In order to solve this problem, an apparatus has been known which has a function for displaying an enlarged image of a part of the field of view on a liquid crystal display. Japanese Patent Laid-Open No. 2012-186670 proposes a method for identifying the position of a feature part included in a subject image through an image analysis process and displaying an enlarged image of the feature part at the identified position on a liquid crystal display in a case where a criterion for enlarged display is not registered. More specifically, in a case where one human figure is a subject, images of both eyes of the human figure are enlarged and are displayed simultaneously. In a case where a plurality of human figures are subjects, images of face parts of all of the human figures are enlarged and are displayed simultaneously.
However, according to Japanese Patent Laid-Open No. 2012-186670, the in-focus direction is not recognized from the enlarged image, and because an MF operation is performed by checking the enlarged image, there may be a possibility that the focus lens may be moved by passing through the in-focus position unintentionally.
Japanese Patent Laid-Open No. 2007-279334 discloses a configuration including a main imaging part and sub-imaging parts for front focus evaluation and back focus evaluation, wherein an in-focus state marker indicative of the in-focus direction is displayed as a result of calculation of the in focus levels of the front focus state and the back focus state. Japanese Patent Laid-Open No. 2007-248615 proposes a method for displaying a bar indicative of a degree of in-focus as a result of calculation of an in-focus evaluation value during an MF operation. Japanese Patent Laid-Open No. 2005-140943 proposes a focus assist method in an imaging apparatus for displaying a plurality of indicators indicative of a change in focusing state caused by a move of a focus lens. Japanese Patent Laid-Open No. 2009-122593 proposes a method for changing a display period of an indicator of a focusing state in accordance with the operation performed on a focus lens.
Displaying the in-focus state marker disclosed in Japanese Patent Laid-Open No. 2007-279334 for each of all feature portions as in Japanese Patent Laid-Open No. 2012-186670 may complicate the resulting image as well as an increase in calculation load. Accordingly, selection of an image region for displaying an in-focus state marker may be expected. However, Japanese Patent Laid-Open No. 2012-186670 does not disclose how an image region for displaying an in-focus state marker is to be set in accordance with a subject. It does not disclose a method for changing the image region for displaying an in-focus state marker in accordance with a user operation.